Filters have been used in aquariums for many years to remove particulate matter from the aquarium water in order to keep the aquarium clean. Traditionally, the most common type of aquarium filter is a power filter which hangs on the outside of the aquarium over the top edge thereof It includes a siphon tube which carries water from the aquarium into the filter box which is located on the outside of the tank. Water entering the filter box flows over various types of filter media to remove particulate matter from the water. The water passes through the filter media to remove chemical impurities and particulate matter from the water which is then pumped back into the aquarium using a filter pump. Typically, the water that is pumped back into the tank is no more than a few inches from the siphon tube that carries he water into the filter, causing ‘dead’ spots in the aquarium where water can stagnate. Further, power filters typically allow debris to collect at the bottom of the aquarium. Examples of such power filters include the Supreme Aqua King power filter marketed by E. G. Danner Manufacturing Co.; the Second Nature Whisper power filter marketed by Willinger Bros. Mfg. Co.; and the Aqua Clear power filter marketed by Rolf Hagen Manufacturing Co.
Another type of aquarium filter hereto used is a canister type filter which is positioned outside and usually below the aquarium. Intake and output hoses hang over the aquarium edge and are connected to the canister filter on the floor. Water is fed by gravity through the intake hose from the aquarium to the canister. The aquarium water is treated mechanically, chemically, and biologically and pumped back into the aquarium by a pump contained in the canister. Canister filters are designed to be a sealed system and the filter and hoses alike must remain water-tight to prevent leaks. Being a closed system, the biological media is completely submersed and may only be aerated through the use of a bubbler added to the water intake. Further, cleaning requires the disassembly and reassembly of the filter. Similar to the power filter, the canister filter typically allows debris to collect at the bottom of the aquarium. Examples of canister type filters include the Hagen Fluval filter marketed by Hagen USA Mfg., Co.; and Marine Land canister filter marketed by Aquaria, Inc.
An internally mounted power filter is still another type of aquarium filter. Such filters comprise a small canister with a built-in pump which is submerged inside the aquarium. Water enters the bottom of the canister and flows through a filter sleeve which removes particulate and chemical waste. The filtered water is then pumped out the top of the canister and back into the aquarium. An internally mounted power filter requires either an air hose or a power cord inserted into the tank and the filter must be completely removed for maintenance. Similar to the canister type filter, the internally mounted power filter incorporates a completely submersed biological media and may only be aerated through the use of a bubbler added to the water intake. Similar to the power filter, the internally mounted power filter typically causes ‘dead’ spots in the aquarium where water can stagnate. Also similar to the power filter, the internally mounted power filter typically allows debris to collect at the bottom of the aquarium. Examples of this type of filter are the Supreme Ovation internal filter marketed by Danner Mfg. and the Hagen Fluval internal filter sold by Hagen USA Mfg. Co.
Still another type of filter employed in aquariums is the undergravel filter which consists of a perforated raised plate which rests on the aquarium floor. Riser tubes are provided on either end of the filter and extend into the top of the aquarium. Gravel is placed on top of the plate to a thickness of about 2″. Air lines from an external pump are placed in the riser tubes to the bottom plate and an air stone is placed at the end of the air lines. Air is forced by the pump to the air stones thereby forcing air bubbles to travel up through the tubes to the water surface creating turbulence or current. Water is then pulled through the gravel and forced up the riser tubes. Alternatively, a pump may be placed on top of the riser tube to force water into, or pull water from the tube. Chemical or mechanical pre or post-filters may be used. Waste from the aquarium is drawn through the gravel bed where bacteria break down any ammonia or nitrites to less harmful nitrates. Typically, in an undergravel filter that pulls water through riser tubes, the aquarium gravel itself becomes a mechanical filter, trapping debris which then must be regularly maintained. Further, in an undergravel filter, a large portion of the aquarium is occupied with air-stones, air hoses, pumps, pre-filters, power cords and riser tubes. Additionally, the surface area of the substrate in an undergravel filter can cause ‘dead’ spots in the aquarium where water can stagnate. Examples of such undergravel filters include filters marketed by Perfecto Mfg. and Penplex Mfg.
Yet another type of filter commonly used in aquariums is a wet/dry trickle type filter which includes a skimmer box or tube that is placed inside the aquarium at the surface of the water. Siphon tubes are provided for carrying water from the aquarium to a pre-filter which is typically mounted directly behind the skimmer box on the outside of the aquarium. Water passes through the pre-filter to trap particulate matter. The water then travels through the hose into a tank typically positioned beneath the aquarium. As water enters the tank beneath the aquarium, it flows onto a drip plate or spray bar in a dry chamber of filters which contains a high surface area media suitable for bacterial colonization. Water drips over and through the media to the bottom section of the tank. Bacteria colonies grow on the media, which feed on waste products in the water passing over them. From there, the water gathers in the bottom of the filter tank and then passes through a carbon filter or other filter to remove chemical wastes from the water. The water is then pumped through the return hose back to the aquarium. Wet/dry filters can include mechanical, chemical and biological filters. Wet/dry trickle type filters require external hosing that must remain water-tight to prevent leaks. Further, wet/dry trickle type filters that utilize a siphon box must be regularly maintained to prevent siphon loss, which may overflow the aquarium. Similar to the power filter, the wet/dry trickle type filter typically causes ‘dead’ spots in the aquarium where water can stagnate. Also similar to the power filter, the wet/dry trickle type filter typically allows debris to collect at the bottom of the aquarium. Examples of such filters in the Plus Series trickle filter marketed by Oceanic System, Inc. and the Perfecto Wet/Dry filtration system sold by Perfecto Mfg. Co.
Wet/dry filters may also be built into the aquarium and form a permanent part of the tank. One such wet/dry filter that is permanently built into the tank is marketed by Tenecor Corporation of Tempe, Ariz.
An alternative form of the wet/dry filter is an internally mounted wet/dry filter which includes an integrated pump and heater for small aquariums. The filter is placed inside the aquarium against the rear wall with the top of the filter at the water level. Water enters the filter and then passes through the filter cartridge which removes particulate and chemical waste materials. A portion of the water is then pumped into a drip plate in a dry chamber for biological filtration. The remaining water is then pumped directly back into the aquarium so as to bypass the dry area. Typically, with an internally mounted wet/dry filter, less than 100% of the water exhausted from the filter is biologically filtered. Further, cleaning requires the disassembly and reassembly of the filter. Similar to the power filter, the internally mounted wet/dry filter typically allows debris to collect at the bottom of the aquarium. One such filter is marketed by Rolf Hagen Mfg. under the trademark “Biolife” filter.
Yet another type of internally mounted wet/dry filter is the Simplicity Plus by Tenecor Corporation. The filter is also placed inside the aquarium against the rear wall with the top of the filter at the water level. This filter includes a chamber for a protein skimmer, heater chamber, sump level adjuster, fresh air injection fittings, mechanical and chemical chambers. With this type of wet/dry filter, visibility through the tank is impaired due to the rear-mounting of the filter. Similar to the power filter, this type of wet/dry filter typically causes ‘dead’ spots in the aquarium where water can stagnate. Also similar to the power filter, this type of wet/dry filter typically allows debris to collect at the bottom of the aquarium.
With the exception of the wet/dry filters, none of the filters here perform biological filtration to a modicum of efficiency. Most filters cause ‘dead’ spots in the aquarium where water can stagnate, allow debris to collect at the bottom of the aquarium, are difficult to maintain and are unsightly.
Though the wet/dry filters are somewhat efficient at biological filtration, most create a channeling effect which causes both inefficient water circulation and inefficient biological filtering of the water. Also, most wet/dry filters are complicated to install, are expensive and have involved maintenance requirements. They are also prone to leakage and clogging since the water is removed and then pumped back through the hoses. Additionally, most take up space outside of the aquarium or prevent adequate visibility through the tank.
Moreover, the internally mounted filters have a limited capacity. They do not buffer or completely filter all of the water entering the biological section. The entire filter may have to be removed for maintenance. The biological area uses ceramic blocks for bacteria beds which also create a channeling effect and tend to clog and must be replaced. Moreover, since the water entering the filter comes from the bottom of the filter, they do not skim the surface of the water. Further, though the Simplicity Plus can handle larger aquariums, they are very bulky, taking up a large portion of the living area of the aquarium and viewing through the aquarium is impaired by the rear-mounted filter design.
What is needed, therefore, is a filter that treats the water mechanically, chemically and biologically, provides maximum and uniform circulation and aeration of water, prevents channeling, reduces surface debris, reduces leaking and clogging, maximizes the view able area, facilitates a slim profile, while being uncomplicated to install and inexpensive.